Ensure that "has '+nonexistent'" fails

[gitmo/Mouse.git] / lib / Mouse / Meta / Class.pm

diff --git a/lib/Mouse/Meta/Class.pm b/lib/Mouse/Meta/Class.pm
index ea7c896..6c94c93 100644 (file)
--- a/lib/Mouse/Meta/Class.pm
+++ b/lib/Mouse/Meta/Class.pm
@@ -3,10 +3,22 @@ package Mouse::Meta::Class;
 use strict;
 use warnings;
 
+use Scalar::Util 'blessed';
+use Carp 'confess';
+
 use MRO::Compat;
 
 do {
     my %METACLASS_CACHE;
+
+    # because Mouse doesn't introspect existing classes, we're forced to
+    # only pay attention to other Mouse classes
+    sub _metaclass_cache {
+        my $class = shift;
+        my $name  = shift;
+        return $METACLASS_CACHE{$name};
+    }
+
     sub initialize {
         my $class = shift;
         my $name  = shift;
@@ -18,7 +30,7 @@ do {
 
 sub new {
     my $class = shift;
-    my %args = @_;
+    my %args  = @_;
 
     $args{attributes} = {};
     $args{superclasses} = do {
@@ -49,11 +61,60 @@ sub add_attribute {
     $self->{'attributes'}{$attr->name} = $attr;
 }
 
+sub compute_all_applicable_attributes {
+    my $self = shift;
+    my (@attr, %seen);
+
+    for my $class ($self->linearized_isa) {
+        my $meta = $self->_metaclass_cache($class)
+            or next;
+
+        for my $name (keys %{ $meta->get_attribute_map }) {
+            next if $seen{$name}++;
+            push @attr, $meta->get_attribute($name);
+        }
+    }
+
+    return @attr;
+}
+
 sub get_attribute_map { $_[0]->{attributes} }
+sub has_attribute     { exists $_[0]->{attributes}->{$_[1]} }
 sub get_attribute     { $_[0]->{attributes}->{$_[1]} }
 
 sub linearized_isa { @{ mro::get_linear_isa($_[0]->name) } }
 
+sub clone_object {
+    my $class    = shift;
+    my $instance = shift;
+
+    (blessed($instance) && $instance->isa($class->name))
+        || confess "You must pass an instance ($instance) of the metaclass (" . $class->name . ")";
+
+    $class->clone_instance($instance, @_);
+}
+
+sub clone_instance {
+    my ($class, $instance, %params) = @_;
+
+    (blessed($instance))
+        || confess "You can only clone instances, \$self is not a blessed instance";
+
+    my $clone = bless { %$instance }, ref $instance;
+
+    foreach my $attr ($class->compute_all_applicable_attributes()) {
+        if ( defined( my $init_arg = $attr->init_arg ) ) {
+            if (exists $params{$init_arg}) {
+                $clone->{ $attr->name } = $params{$init_arg};
+            }
+        }
+    }
+
+    return $clone;
+
+}
+
+
 1;
 
 __END__
@@ -86,11 +147,20 @@ Gets (or sets) the list of superclasses of the owner class.
 Begins keeping track of the existing L<Mouse::Meta::Attribute> for the owner
 class.
 
+=head2 compute_all_applicable_attributes -> (Mouse::Meta::Attribute)
+
+Returns the list of all L<Mouse::Meta::Attribute> instances associated with
+this class and its superclasses.
+
 =head2 get_attribute_map -> { name => Mouse::Meta::Attribute }
 
 Returns a mapping of attribute names to their corresponding
 L<Mouse::Meta::Attribute> objects.
 
+=head2 has_attribute Name -> Boool
+
+Returns whether we have a L<Mouse::Meta::Attribute> with the given name.
+
 =head2 get_attribute Name -> Mouse::Meta::Attribute | undef
 
 Returns the L<Mouse::Meta::Attribute> with the given name.